1. Field of the Invention
The present invention relates to a spindle motor and a hard disk drive including the same.
2. Description of the Related Art
A hard disk drive (HDD), an information storage device, is a device for reading data stored on a disc or writing data to a disc with a read/write head.
A hard disk drive requires a disc driving device for driving a disc, and a small spindle motor is used in the disc driving device.
A spindle motor employs a fluid dynamic bearing assembly (or a hydrodynamic bearing assembly), in which a lubricating fluid is interposed between a shaft, a rotary member of the fluid dynamic bearing assembly, and a sleeve, a fixed member of the fluid dynamic bearing assembly, and the shaft is supported by fluid pressure generated in the lubricating fluid.
Here, a lubricating fluid injected into a fluid dynamic bearing assembly may be leaked to outside or an amount of the lubricating fluid may be reduced due to evaporation, reducing pressure generation in a fluid dynamic bearing and leading to a problem with performance and a lifespan of the spindle motor.
Also, in a case in which an internal component of the spindle motor is deformed due to external impacts applied to the spindle motor while the spindle motor is being driven, the driving of the spindle motor is negatively affected, so, it is important to secure rigidity of the spindle motor.
Thus, research into a spindle motor that may have rigidity sufficient to allow an internal component thereof to resist deformation in spite of external impacts applied thereto, and have performance and lifespan maximized by securing a storage space of a lubricating fluid is urgently required to be conducted.